Low pressure code and Engine failure mode. Please help!

[mallard8]

I am still getting a P008A low pressure code on my 21 GT. I have replaced the entire fuel pump, injector rail sensor, and high pressure pump. I have inspected fuel lines to make sure that they are all in the correct direction and orientation and am not sure what else to do. Whenever I accelerate past about 3500, i get a wrench light and the car cuts power and immediately goes into engine management/failure mode.

Got headers, JLT CAI, and full exhaust, and previous owner did remove a supercharger before selling. I attached my latest datalog.
Any suggestions are really appreciated, i need help!

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[NGOT8R]

Is the fuel system still the factory returnless (minus the upgraded pump)? Double check your fuel line where it transitions from stainless steel to nylon to make sure there’s no rupture.

https://www.mustang6g.com/forums/threads/2019-bullitt-fuel-line-leak.197116/

Before the ruptured fuel line, I also had a pump go bad and throw codes as well. See thread here.

https://www.mustang6g.com/forums/threads/suspected-bad-fuel-pump-2019-bullitt-on-e85.189945/

 

[mallard8]

Is the fuel system still the factory returnless (minus the upgraded pump)? Double check your fuel line where it transitions from stainless steel to nylon to make sure there’s no rupture.

Sorry, I meant i replaced the pump and sending unit as a whole with a OEM motor craft one. Previos owner has installed a DW400 and there was a bunch of gunk in the housing an under the filter sock. Ill check the lines.

 

[NGOT8R]

Sorry, I meant i replaced the pump and sending unit as a whole with a OEM motor craft one. Previos owner has installed a DW400 and there was a bunch of gunk in the housing an under the filter sock. Ill check the lines.

You mean gunk in the fuel pump bucket? How many miles on the car? Can you pull the rubber cover to the fuel pump well and have someone cycle the ignition while you shine a light in there and take a good look/listen. If there’s a leak, you’ll see fuel misting in that area and hear air as well.

 

[SheepDog]

I am still getting a P008A low pressure code on my 21 GT. I have replaced the entire fuel pump, injector rail sensor, and high pressure pump. I have inspected fuel lines to make sure that they are all in the correct direction and orientation and am not sure what else to do. Whenever I accelerate past about 3500, i get a wrench light and the car cuts power and immediately goes into engine management/failure mode.

Got headers, JLT CAI, and full exhaust, and previous owner did remove a supercharger before selling. I attached my latest datalog.
Any suggestions are really appreciated, i need help!

Well,

The PCM is pulling 5 degrees of timing at around 3000 RPM

and you are knocking like crazy Through the rest of most of your pull. Stop doing pulls until you figure this out. Why aren't you logging fuel rail pressure?

THE PCM is adding fuel denoted by the .75 AFR on both banks

Have you done a compression test? What do the spark plugs look like?

 

[mallard8]

Well,

The PCM is pulling 5 degrees of timing at around 3000 RPM

and you are knocking like crazy Through the rest of most of your pull. Stop doing pulls until you figure this out. Why aren't you logging fuel rail pressure?

THE PCM is adding fuel denoted by the .75 AFR on both banks
Have you done a compression test? What do the spark plugs look like?

I haven't done a real pull in about 2.5 weeks. I've been driving the car under 3k rpm for a while. I'm not sure why that isn't logged. I had the HPFP installed while I was out of town by a friend who used to be a Mustang tech, he said that it's running 20 psi high on the low side and 20 low on the high side. Have not checked the plugs, also was told to check the follower on the passenger side camshaft in between the pump and cam, the lobe on that side is how it was described to me.

 

[mallard8]

You mean gunk in the fuel pump bucket? How many miles on the car? Can you pull the rubber cover to the fuel pump well and have someone cycle the ignition while you shine a light in there and take a good look/listen. If there’s a leak, you’ll see fuel misting in that area and hear air as well.

Yes gunk in the actual bucket. about 14k on it right now. when i installed new pump i did listen for any sounds, did not hear any air or see any mist or fuel puddled up.

 

[SheepDog]

I haven't done a real pull in about 2.5 weeks. I've been driving the car under 3k rpm for a while. I'm not sure why that isn't logged. I had the HPFP installed while I was out of town by a friend who used to be a Mustang tech, he said that it's running 20 psi high on the low side and 20 low on the high side. Have not checked the plugs, also was told to check the follower on the passenger side camshaft in between the pump and cam, the lobe on that side is how it was described to me.

Did the previous owner also have an aftermarket fuel system on it?

 

[NGOT8R]

Yes gunk in the actual bucket. about 14k on it right now. when i installed new pump i did listen for any sounds, did not hear any air or see any mist or fuel puddled up.

Click on this link again and watch the video at the bottom of post #4. You will see fuel mist and hear air when I cycle the ignition. When you pull the rubber cover to access the fuel pump, look toward the front of the tank (about the 11 O’clock position) when you cycle the ignition to see if anything abnormal is going on.

https://www.mustang6g.com/forums/threads/2019-bullitt-fuel-line-leak.197116/

 

[mallard8]

Did the previous owner also have an aftermarket fuel system on it?

No, All he had installed was the DW400 pump, everything else was stock including injectors and all that

 

[SheepDog]

No, All he had installed was the DW400 pump, everything else was stock including injectors and all that

You might try backflushing the fuel feed line ( a PITA for sure) High pressure on the low side, and low pressure on the high side may indicate a partial blockage somewhere.

You do need to log fuel pressure and see what the rail sensor is seeing

 

[Mike Pfeifer]

Did the previous owner run E85? I have heard that E85 will lead to gunk building up, maybe there is a lot of it floating around and it’s clogging things up. If so, that’s going to be a real pain to clean up unfortunately.

 

[NGOT8R]

Is there a Boost-a-Pump on the car? If so, are there two wires (maybe gray and black) up near the throttle control switch coming off of the BAP wiring harness that may be touching each other intermittently? If the answer is “yes”, separate those two wires and either cut the ring terminals off, or cover them with heat shrink. Then test again to see if the problem clears up.

 

[NGOT8R]

Something else to look out for that will give you a clue as to whether the car has an E85 tuneup in it, is to look at the Air Fuel gauge on the dash and if it reads 9.8 or so, you have an E85 tune in it. That would be problematic if you’re running 93 fuel on an E85 tuneup.

 

[mallard8]

Is there a Boost-a-Pump on the car? If so, are there two wires (maybe gray and black) up near the throttle control switch coming off of the BAP wiring harness that may be touching each other intermittently? If the answer is “yes”, separate those two wires and either cut the ring terminals off, or cover them with heat shrink. Then test again to see if the problem clears up.

No BAP that i can see. Ill double check but i don't think there is anything like that

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